Originally Posted by
birmingham
Ruthenium 106 apparently has a half life of 15 days and would only have been of concern close to the source.
106Ru half life is 373.59 days, not 15, but it emits beta particles (electrons) that don't travel further that a few centimeters, so you need to have it on your body to be dangerous.
Levels of it high in the air are very low, so don't worry about the flight.